Reduced Tillage: Alternative Cropping Systems for Vegetable Production in the Northeast

Reduced Tillage: Alternative Cropping Systems for Vegetable Production in the Northeast

Summary

We are proposing to investigate the use of reduced and strip-tillage with interrow cover crops for vegetable production in the northeast. The research will be conducted at research facilities and growers' fields in upstate New York and on Long Island, and in Connecticut.

We will evaluate different grass and legume mulch/cover crop species for their ability to suppress weeds, conserve soil moisture and control soil erosion. Crop performance in each of the mulch systems will be determined and herbicide rates will be reduced utilizing the weed-suppressing potential of the mulches.

The studies will be conducted on a wide range of crops that are grown throughout the northeast and north central regions of the US. We will include tomatoes, cabbage or cauliflower, snap beans, sweet corn and pumpkins at multiple locations. The proposed research will help to define the specific requirements for reduced-tillage vegetable production that will be necessary if growers are to consider using such systems. Formulation of such recommendations in combination with the extension and education efforts involved in this project should provide commercial interest and participation in a system with both economic and environmental advantages.

Objectives

We are proposing to investigate the use of reduced and strip-tillage with interrow cover crops for vegetable production in the northeast. The specific objectives of the proposed work are:

(1) Evaluate potential cover crop/mulch species for their ability to suppress weeds, conserve moisture and reduce erosion. Growth characteristics like rate of growth, biomass production, degree of tillering and plant architecture will have a significant impact on the degree of weed suppression and soil and water conservation achieved. For example, the vertical architecture of the grass mulches may allow more water evaporation than the horizontal covers provided by legumes. Conversely, the potentially greater moisture under the legume mulch may enhance weed germination. Differences in light penetration in the two mulch types may result in changes in the species of weeds that germinate and develop.

(2) Determine the yield potential of numerous vegetable crops grown throughout the northeast when produced in strip or reduced tillage systems. Numerous problems have been reported when vegetables are grown in no-tillage systems. Three of the commonly reported problems are poor seed-soil contact or coverage; cold soils preventing germination; and reduced root development. We feel that the use of strip tillage, particularly coupled with the use of a chisel tine in the strip, will alleviate these problems. Our goal is not to obtain increased yields in these systems but to obtain yields equivalent to those currently produced with traditional plow/disc cultivation systems.

(3) Utilize the weed suppressing potential of a mulch to reduce rates of applied herbicides. In order to significantly reduce the chemical load on the environment we must convince large-scale commercial vegetable growers that herbicide use can be reduced without a reduction in yields (profits). Through a combination of physical and allelopathic characteristics some mulches prevent or suppress weed germination and/or growth. Delaying weed emergence by four to six weeks would eliminate the need for most soil-applied preemergence herbicides. Coupled with the currently labeled, highly selective post-emergence herbicides, growers can begin to apply herbicides at low dose on an as-needed basis as is done with insecticides and fungicides in traditional Integrated Pest Management Programs.

(4) Compare costs involved with each mulch/tillage/herbicide system. Each mulch used will require a different management approach; spring oats will winter-kill; hairy vetch will be mowed; and the remainder will require chemical regulation. It will be necessary to calculate all inputs into the system: man and machine time, fuel and chemical inputs, etc. It may prove that reducing the chemical inputs in dollars will be offset by increases in the other areas, however the benefit of reducing the chemical load on the environment and of reducing soil loss must also be factored into the economic equation.